Straight and automatic air brake



y 1935. N. A. CHRISTENSEN Re. 19,650

STRAIGHT AND AUTOMATIC AIR BRAKE SYSTEM Original Filed 001;. 26, 1925 5 Sheets-Sheet 1 1 NTOR.

- ATI'ORNEIIS 5 Sheets-Sheet 2 INVENTOR lV/[LS A CEISTf/VSf/V A TTORNE Y v N. A. CHRISTENSEN Original Filed' Oct. 25. 1925 July 23, 1935.

s'rnuea'r AND AUTOMATIC AIR BRAKE SYSTEM [III II July 23, 1935.

N. A. CHRISTENSEN STRAIGHT AND AUTOMATIC AIR BRAKE SYSTEM 5 5 Sheets-Sheet 3 Original Filed'Oct. 26, 192

} amt N/ELS A. (FISTi'A/Sf/V July 23, 1935. N. A. CHRISTENSEN 19,550

STRAIGHT AND AUTOIATIC AIR BRAKE SYSTEM Original Filed Oct. 2 6 1925 5 Sheets-Sheet 4 gwocntov July 23, 1935. N. A. CHRISTENSEN STRAIGHT AND AUTOMATIC AIR BRAKE SYSTEM Original Filed Oct. 26, 1925 5 Sheets-Sheet 5 iii/l/IIIIIII/I/I/II/li.

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IN VENTOR lV/[ZS A. CF/JTFNJf/V A TTORNE Y3 Reissued July 23, 1935 UNITED STATES PATENT OFFICE STRAIGHT AND AUTOMATIC AIR BRAKE SYSTEM Niels A. Christensen, Cleveland, ohm

Original No. 1,614,652,

dated January 18, 1927,

15 Claims.

The invention relates to air brake systems for vehicle trains.

The object of the invention is to provide a brake system for operating and controlling air or fiuid-pressure-operated brakes on vehicle trains, whereby the advantages of straight air brake application may be obtained, and automatic air brake application may be had in case the vehicles of the train should pull apart or otherwise become. separated from the main or driving vehicle.

The invention further consists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings, Fig. l is a diagrammatic view of an air brake system embodying the invention;

Fig. 2 is a side elevation of one of the valve mechanisms employed in the system;

Fig. 3 is a section taken on the line 3-3 of Fig.

FiFigs. 4 is a. section taken on the line 4-4 of Fig. 5 is a detail sectional view through a check valve in one of the pressure lines;

Fig. 6 is a detail sectional view through the operator's control valve;

Fig. 7 is a detail sectional view through the control valve on one of the trailers;

Fig, 8 is a vertical sectional view through the 30' coupling between the vehicles;

Fig. 9 is a vertical sectional view through the triple valve mechanism for the hauling vehicle. shown in an intermediate position;

Fig. 10 is a vertical sectional view showing the triple valve for each of the trailer vehicles, showing it in application position;

Fig. 11 is a view similar to Fig. 10, showing the triple valve in release position.

In order to cut oiT the escape of air from the main reservoir pipe line, in case the vehicles of the train pull apart, cut-oil valve mechanism ll, shown in Figs. 2 to 4, inclusive, is provided. This valve mechanism includes a two-part casing I4 and I5 secured together by bolts I5, and is inserted in the reservoir pressure pipe 35 on the hauling vehicle and includes an inlet passage 11 and an outlet passage I8, with a valve seat l9 adapted to cooperate with a valve so as to close off communication between the inlet and outlet ends l1 and I8. The valve 20 has its stem slidably mounted in a stufling-box 2| in a plug 22 secured to the casing l4, and is normally held in an open position by a spring 23 interposed between the plug 22 and a nut 24 on the valve stem.

Under certain conditions hereinafter described, the valve 20 is moved to closed position against the seat I! by compressed air received from the auxiliary reservoir of the hauling vehicle, and for this purpose the upper end of the stem engages a thimble which works in a bore 25 in a, piston 21, and a. spring 28 is interposed between the thimble 25 and the piston 21. The spring 23 permits relative movement between the thimble 25 and the piston 21 and transmits forces 10 imparted to' the piston to the thimble 25 to cause the valve 20 to be seated. The piston 21 works in a. bore 29 in the casing section I5, whose upper end is closed by a cap 30 having a port opening 31.

The lower end of the piston 21 is bevelled to form an annular valve 32 which cooperates with a seat 33 formed at the lower end of the bore 29. A vent passage 34 is provided in the casing l5. When compressed air passes through the port 20 3i and exerts pressure against the piston 21, this force is transmitted through the spring 28 and thimble 25 against the stem of the valve 20 and the parts move downwardly to close the valve 20.

As the piston 21 is not packed, during this move- 25 ment some of the compressed air may pass between the piston and the casing 15 and is permitted to escape through the vent 34. When, however, the valve 20 is moved to a closed position the piston 21 moves down so that the valve 30 face 32 engages the seat 33 and thus seals the vent passage 34, this movement occurring after the valve 20 has been seated on its seat 19 and the spring 23 permitting of this movement of the piston 21 after the thimble 25 has stopped its 35 movement. The seating of the piston 21 in the manner above described cuts oiT further leakage of air from the main reservoir through the outlet 13 and thereby conserves the air in the brake system.

The casing 14 has a. passage 31 communicating with the inlet opening 11 and with passages 38 and 33, and the outlet end 18 has a passage 40 communicating with the passage 38 through holes ll in a screw-plug 42. The passages 39 and 43 45 communicate with a passage formed by bores 43, H and IS. The bore 44 communicates with a port 46 and the passage 38 communicates with a port 41.

A ball valve 48 works in the enlarged bore of 50 the passage 38 and is adapted to seat either against the end of the tubular plug 42 or a. seat 45, so that under some conditions the air entering from the inlet I1 passes down through the passage 31 to the passage 38 and out through the port 41, the ball 48 then closing off communication with the outlet l8 and the passage 40, and under other conditions the ball 48 is moved over into engagement with the seat 4! and air from the outlet end may then pass down through the passage II), holes H, into the tubular portion of the cap 42 and out through the port 41. The was sage of air to the port 46 is controlled by ball valves 50 and SI, which may, respectively, seat at the respective ends of the reduced bore ll and are limited in their outward movement by stops 52 forming the ends of screws 53. A cross-shaped distance piece 54 works in the bore II and is of a length so that when one of the balls 50 or 5! is seated the other is held off its seat. When the ball 50 is all its seat, air from the inlet Il may pass from the passage 31 to the passage 35, bores 43 and M, to the port 46. When the ball 5! is oil" its seat air may pass from the space 48 through the bores 45 and M to the port 48.

The port 41 is connected by piping to the triple valve mechanism of the hauling vehicle and to the brakes. As shown, this piping for the driv ing vehicle includes a pipe 55 having a branch pipe 56 connected to the control valve mechanism 51, and branches 59 and 59 connected, respectively, to the auxiliary reservoir GI and the head end of the triple valve mechanism for the hauling vehicle.

Referring to Figs. 9, i and 11, the triple valve mechanism, which is mounted on each of the vehicles of the train, includes the auxiliary reservoir i and a housing 62 including a cylinder 63 in which the valve-operating piston 54 works. This piston is provided with the usual packing ring 65 and its rod 55 works through the rear end of the cylinder 53 and is slotted at 81 intermediate its ends and provided with a cross-pin i8. and the depending slotted end 59 of a T-headed lever engages this pin within the slotted portion of said rod and is therefore moved by the pin 64. The lever ii! is mounted on a fulcrum pin 1| carried by a depending part 01' the valve hous.- ing I2 containing valves 13 and Il urged to their seats by springs mounted between the tubular parts of said valves and the box-nuts 15. These valves 13 and 14 are respectively operated by pins 11 and 18 which are tapered toward their stems to allow of the graduated control of the passage of air through the ports I9 and B0. The status of said pins are preferably packed by suitable stuffing boxes 8|. The valves 13 and I! are held tightly to their seats by their springs unless opened by the lever 16 whose arms, upon the swinging of said lever by the piston BI and its rod, are adapted to alternately open and close said valves by movement of the operating pins 11 and I8. The housing I2 is securely mounted in an air-tight manner upon the housing 62.

The valves I3 and I4, respectively, work' n chambers 82 and 83 which communicate, respectively. when the valves are open, with the ports 19 and 80, The port 19 communicates with a passage 84 connected by a pipe 85 with the exhaust of either of the control valves 51 or 58, said passage 3! also communicating with the chamber 83. The bore 80 communicates with a duct 86 leading to atmosphere.

Main reservoir pressure in pipe 38 is introduced into the forward end of the cylinder 63 through a passage 81 which, in the case of the hauling vehicle, is connected by piping 88 to the port I of the valve mechanism previously described in the case of each trailer vehicle by piping ll. The rear end of the cylinder 08 communicates with the auxiliary reservoir I through a port 9, chamber 90 and port 9!. There is sufllcient leekage between the piston 54 and its cylinder to allow compressed air to equalize itself on both sides of the piston and to allow compressed air to pass around said piston through the passage Just mentioned to the auxiliary reservoir 8! to fill it with air to the same pressure as that in the main reservoir.

A spring 92 is interposed between the reduced end of the passage 81 and the head end of the piston and is of a strength to normally move the piston toward the auxiliary reservoir so as to maintain the exhaust valve 14 in open position, as shown in Fig, 11, and keep the inlet valve 33 closed.

A passage 93 connects the space 50 with the chamber 82. For the hauling vehicle the front head 93 for the cylinder 63 has passages BI, 95 and 95, and a valve 91 controls the passage of air from. the passages 94 and 95 to the passage 96. This valve is of the same type as the triple valves and is normally held closed by a spring 98 and opened by a pin 99, similar to the operating pin I1. and its stem Hill projects into the cylinder 63 so as to be engaged by the piston 84 as said piston reaches the end of its brake-applying stroke.

The pipe 60 connects with the passage 98 and a pipe ml connects the passage 96 with the port 3! in the automatic valve mechanism previously described. In addition, the head end 98 of each triple valve cylinder has 9. rounded scat I82 formed thereon which cooperates with a composition disk I03 on the front end of the piston to seal the bore ill and the piping connected therewith to prevent the escape of air at auxiliary reservoir pressure when said piston BI is at the end of its brakc-applying stroke, that is, when it is moved against the head 93 and has operated the pin NIH.

The control valve mechanisms 51 and 58, shown in'Flgs. 6 and 7, are similar, except as to their operating means. The control valve mechanism 51 includes a casing I04 having a space Hi5 there in, including a bore I06. A brake pipe passage Hi5, a valve-controlled exhaust passage Hi5, and a valve-controlled inlet passage 1 ll communicate with the space I05. A relief valve II I controls the flow of compressed air from the space M5 to the passage I09 and thence through passages here inafter described to atmosphere, and an inlet valve l 52 controls the flow of compressed air from a chamber H3 to the space I", and the pipe 56 is in communication with the chamber H3. The passage I08 is connected by suitable piping lit to the brake cylinders H5 associated with the wheels of the driving or hauling vehicle. The piping II connected with the control valve El is connected by piping ill on the hauling vehicle to piping III! on each of the trailer vehicles through couplings H9 hereinafter described. A pipe I connects the control valve 58 of each. trailer to its pipe H8.

The inlet valve H2 has a tubular portion slidably mounted in the bore of a box-nut III and is held against its seat III by a spring in interposed between the end of said bore and the outer end 01' the bore in the nut III. A push-pin i2 is slidably mounted in the passage Hi and has a. stem portion mounted in a bore I15 formed in the casing. The head of this pin engages the head of the inlet valve j I! and may be of tapered form for graduating the passage llfl. A piston I21, formed of parts I18 and I2! and a. flexible packing I", works in the bore IE6 and, is moved in one direction by pressure e of air through the transmitted to it from a plunger I3I, by a spring I32, and in the opposite direction by fluid pressure acting against its inner end. The part I23 has a recess in which the spring I32 seats and a. threaded tubular end portion I33 with a bore I34. The part I29 has threaded engagement with the portion I33, whereby the medial portion of the packing disk I is clamped between said parts, and it has bores I35 and I36 alined with the bore I34, the bore I35 being of smaller diameter than the bore I36 to form a. stop flange I31.

The relief or exhaust valve II I is in the form of a poppet needle type valve having a conical head adapted to seat on the inner end of the passage I09 and having a tubular stem provided with a flange I38 and a bore I39. A spring I40 is mounted in the bore I33 and interposed between the end of said bore and the inner end of the bore I34, and said spring normally acts to move the valve III so that its flange I38 abuts against the flange I31. The valve III is not responsive to the air pressure in the space I05 to effect its opening but its change in position is due directly to the position and movement of the piston I21.

The plunger I3I has a spring-seating flange I H and a cylindrical tubular guide portion I42 which is guided in a tubular extension I43 secured to the casing I04 by screws I44 passing through flanges on the casing and said extension. said extension I43 having vertically disposed slots I45 therein. The end of the cylindrical guide portion I42 has a vertically disposed slot I55 formed therein and carries a pin I41. Spaced lugs IE3 are also provided on the extension I 43, having a fulcrum pin I49 mounted therein.

A foot-pedal or lever I50 is pivoted on the pin I40, works in the slots M5 and I46, and has a slot I5I through which the pin I41 passes. This lever, by means of a spring E52 secured to it and to a stud I53 mounted on the casing, is moved, with the plunger I3I associated with it through the pin-and-slot connection above described, to its outer position in which the spring I32 is relieved or substantially relieved of its tension. when, however, the operator presses down on the lever I50, the plunger I! is moved inwardly, putting a tension on the spring I32 which thereby transmits its force to the piston I21, causing it to move inwardly.

The casing I04 is provided with a flange I54 for conveniently mounting on the dash I55 of the driving vehicle, and the spring I52 works through a hole I56 in the dash.

The piston I21 may move with the plunger I3I near the end of the outward movement of the plunger I3 I because of a connection between these parts consisting of a screw I51.

As shown in Fig. 6 the parts are in non-application position, and it will be noted that the relief or exhaust valve II I is open and that the stem of the operating pin I24 is spaced from the Inner end of the piston at a greater distance than is necessary to cause the travel of said piston to seat the valve III.

To make a brake application the operator presses down on the lever I50 and moves the plunger I3I inwardly which, through the spring I32, causes an inward movement of the piston I21 and this in turn, through the spring I00, causes the exhaust valve III to be moved to its seat to close off the exhaust passage I03. Further inward movement puts pressure upon the valve III through compression of the spring I40 and then causes the piston I21 to engage the pin I24 and move it to open the inlet valve I I2, whereupon the compressed air coming from the reservoir 35 through the pipe 35, the cut-off valve previously described, and the pipe 50. enters the space I05 and thence passes through the passage I03 to the brake pipe I" and thence to the brake cylinders I I5. As the pressure in the brake system builds up the pressure in the space I05 in front or the piston I21 increases until it overcomes the pressure being exerted by the operator through the spring I32, and when said pressure exceeds the pressure of the spring I32 the piston I21 travels away from the stem of the pin I24 and the inlet valve II2 closes and the parts are then in a "lap" position, since the piston travel then is not suflicient to relieve the pressure on the spring I40 to such an extent as to permit unseating of the valve III which, it will be noted, has a greater tendency to remain seated because of the pressure in the chamber I05 than to be opened because of the differential area of the seat and the valve. Thereafter release of the pressure on the spring I32 by release of the pressure on the foot-pedal will cause the piston I21 to travel outward, due to pressure exerted on it by the compressed fluid in the space I05, and when the flange I31 engages the flange I38 it will cause an opening of the relief valve HI and an exhaust 01. air from the brake system, since the exhaust passage I09 is connected by a pipe I53 to the port 84 of the triple valve mechanism which communicates with the chamber 83 and the exhaust passage 85, which last-named chamber and passage are in communication with each other by the then opened condition of the exhaust valve 1% of the triple valve mechanism on the driving vehicle, i

this valve being open at that time because the spring 92 has moved the piston 55 to a release position.

Each of the control valves 50 or the trailer vehicles includes a casing 05, similar to the casing I00, provided with a brake passage 555 and an exhaust passage I09 and an inlet passage iii. A relief valve HI controls the passage of air through the passage I03 and an inlet valve H2 controls the passage of air from the chamber I E3 1 through the passage H0. The passage IE8 is connected by suitable piping II4' to the brake cyiinders H5 associated with the trailer on which control valve 58 is mounted. A pipe 55' connects the auxiliary reservoir 5| of each trailer with the chamber 3' of its control valve and a pipe 35' connects the passage I03 of each trailer control valve with the passage 34 of its triple valve mechanism, which is similar to that on the driving vehicle and similarly referenced, and the pipes associated with the cut-oil valve mechanism for the trailer and the head end of the triple valve mechanism are similarly referenced as 00 and III.

The parts I2! to I34, inclusive, are similar to parts III to I38, inclusive, of the valve 51 and similarly mounted and arranged as in the previoufiy described construction with the exception that the plunger I3I' of the valve 50 does not have a slotted end but abuts against a suitably packed piston I50 which works In a bore I53 formed in the extension I50 bolted to the case I04, and a spring IiI is interposed between the piston and a guide I02 for the plunger I3I' and acts to move said piston outwardly. Compressed air is introduced from the pipe I20 through a port I03 against the piston I50.

A bolt I51' extends through the plunger III and connects the piston I21 with the piston I55 but permits the piston I21 to move relative to the plunger HI and the piston I58. The piston I58 is substantially of the same diameter as the compensating piston II? in the valve proper. Thus. when the operator steps on the foot-pedal i5il and admits air into the brake pipes i ll, some of this air passes through the piping Ill and H8 to the pipes 120 associated with the control valves 58 on each of the trailer vehicles. This air acting against the piston I58 each valve 58 moves the plunger Hit and thereafter through the springs i32' moves the piston 12'! and effects the closing of the exhaust valves H I and the opening of the inlet valves H2 in the same manner that the exhaust valve Hi and the inlet valve H2 are operated in the master valve 51, and the compen sating action previously described in connection with the main control valve 51 is similarly effected by similar parts in the valves 58 of the trailers. Thus, the operation of the master valve by the operator causes an introduction of compressed air to the pipes 56' and thence to the brake system of each trailer, including piping H5 and the brake cylinders H5,

The compensating action above referred to is effected in each of the valves 58 since when the pressure builds up in the chamber I05 to close oil the inlet valve II! this same pressure builds up in the chamber 105' to close off the inlet valve H2, and the closing off of the inlet valve H2 stops further building up of pressure in the piping, including the pipe I28 associated with the piston I58. The spring lil is a comparatively light spring and is used more particularly to overcome the friction of the piston I58 to return it to a released position.

The pipes ill and H8 and the sections of the pipes H8 between each trailer may be connected by a suitable coupling in which provision is made for sealing the end of each of these pipes when the vehicles are uncoupled. The sections of the reservoir pressure pipe 35 may also be provided with a suitable coupling, but I prefer to use a single coupling device for the pipes 38 and the pipes ill and H8 or pipes H8, and such a device is shown in Fig. 8. As the particular construction of this coupling has been made the subjectmatter of a separate application it will be only briefly described here.

This coupling includes a pair of interlockable coupling members I66 having passages 55 and 858 therein. The passages I65 communicate with each other through an annular space it? formed by cooperating annular flexible packing rings I55. each or which is secured to its respective coupling member by a metal ring I65 and bolts H0. The passages I86 communicate with each other through a central passage i'll formed by the abutting rings I88, and a spring-pressed check valve H2 is mounted in each of the passages I66 and urged by a spring I13 to close oil said passage when the coupling members become separated, but when the coupling members are coupled together the pin extensions Ill 0! these valves are brought into abutting engagement with each other and move the valves of! their seats so that a through passage of air is established between the pipe H1 and the pipe H8. The pipe N8, of which a section is provided on each trailer, extends the entire length of the train and with the pipe sections 35 is coupled together between each of the trailer vehicles by a coupling device similar to that just described.

Manually-operable cut-01f valves I15 are provided inthe reservoir pipe line 38, as well as for the brake pipes ill and Ill, and air strainers I16,

of any suitable construction, are also provided in the reservoir and brake pipe lines.

With the above construction, under normal coilditions compressed air passes from the main reservoir 35 through the reservoir pipe 35, the valve 20 of the cut-off valve mechanism 52 being then open, and through the port El by way of either of the passages El, 39, 38 or 40, ll, 38 to the pipe 55 and thence through the pipe 58 to the auxiliary reservoir of the hauling vehicle, and at the same time air may pass past either one of the balls 58 or 5| to the port 45 and thence through the pipe 38 to the head end 0! the triple valve piston of the hauling vehicle. Under these conditions also air from the reservoir pipe 38 passes through the pipe 88 on each trailer to the passage 81 of the triple valve mechanism of each trailer and past its piston and through port 89, chamber 90, port 9!, to its auxiliary reservoir 6i. Thus, compressed air from the main reservoir is introduced into the auxiliary reservoirs of each vehicle of the train.

Under these conditions pressure on both sides of the triple valve piston B4 of each of the triple valve mechanisms is equalized, and in ,each instance the spring 92 moves and maintains said piston in a release position, thereby holding the exhaust valve H of each triple valve mechanism open and hence the valve 91 associated with the triple valve mechanism of the hauling vehicle remains closed. The apparatus is then in a condition for straight air brake application and remains in this condition unless the couplings IIS pull apart.

When it is desired to apply the brakes to the vehicle train, the operator presses down on the foot-pedal 15D and this closes exhaust valve Ill and opens inlet valve H2 thereby admitting compressed air from the main reservoir through the pipe 58, chamber H3, passages H8, H35, #08 to the piping H4 and thence to the brake cylinders H5. as well as compressed air from the auxiliary reservoir 5! of the driving vehicle by way oi pipes 58 and 55 to the pipe 56.

As soon as compressed air is admitted into the brake piping lid of the main vehicle, some of this air passes through the pipe ill to the piping i l8, from which it is taken off by the pipe ill) on each trailer vehicle to the head end of control valve 58 of that vehicle and acts against the piston 558 of this control valve to close the relief valve ill and open the inlet valve Ill, and thereby admit compressed air coming from the auxiliary reservoir 6! on this vehicle through pipe 56 into the chamber I05 and to passage I08, piping H4 to the brakes H5. Thus, the introduction of air into the brake system of the hauling vehicle, by the operator's operation of the master control valve 51, operates the control valve 58 of each of the trailers, which causes an admission of compressed air from the auxiliary reservoir of each trailer into the brake system of that trailer.

Whenthe operator releases the brake pedal [58, thereby closing the inlet valve l H, he causes the opening of relief valve H I. As soon as the relief valve IH opens pressure in the brake system I I4, I I5 drops, causing a release of the brakes in the hauling vehicle, the air exhausting through the passage I09 by way of pipe 85 and the triple valve of this vehicle through passage 88, chamber 83 and port 88 to atmosphere. The release of air in the piping H4 causes a release of train-pipe pressure in the piping Ill and 8 so that the control valves 58 move to release position, that is,

the inlet valve I I2 closes and the exhaust valve Ill opens, allowing the air in the brake system Ill, I I5 of each trailer to exhaust to atmosphere by way of pipes and passage 84, chamber 83 and port 86 of its triple valve mechanism.

Furthermore, it will also be understood that the control valves 51 and 58 allow of a graduated release or brake application due to the compensating pistons I21 and I21.

Thus, for straight air brake application the triple valve mechanism remains in release position and speedy application of air to the trailer vehicles is assured by the direct passage of air from their auxiliary reservoirs through their control valves to their brake pipes and cylinders, and also a speedy release is obtained through the open exhaust valve of the triple valve mechanism.

In case the vehicles pull apart at the couplings, the valves I12 close off the open ends of the piping H1, H8, or IIB between the vehicles and the escape of air in the main reservoir pipeline causes a release of air from the front ends of each of the triple valve mechanisms of the trailers through the pipes 88 and 35, thereby causing a reduction in pressure in their cylinders 63 ahead of the triple valve pistons 64, and hence unbalancing the air pressure on these pistons, which causes the pressure of air from their auxiliary reservoirs to act on their pistons to move them, as shown in Fig. 10, to brake application position, thereby closing their exhaust valves it and opening the inlet valves l3 by the levers l0 and pins H and thus admitting compressed air from said reservoirs through passages 9!, chain her 90, passages 53 and B4 to the pipe 35, the then open passage HIS, chamber 15', brake piping ill to the brake cylinders H5, so that the brakes are automatically applied to the trailer vehicles through the automatic operation of their triple valves, and when in applied position seating of the seat or valve I03 on the seat it? cuts off escape of pressure from the auxiliary reservoirs of the trailer vehicles.

A similar action takes place in the triple valve mechanism of the hauling vehicle since the cut" oil valve mechanism operates to close the valve 20 and open the pipe 88 to atmosphere, thereby unbalanclng the piston 64 of the triple valve of the hauling vehicle and causing it to function in the same manner as the triple valves of the trailer vehicles to open its inlet valve 13 to admit air from its auxiliary reservoir by way of passage Bl, chamber 80, passages 93 and 84 to pipe 85, then open passage I09, chamber I06, brake piping II to the brake cylinders H5 so that the brakes are automatically applied to the hauling vehicle through the automatic operation of its triple valve, and when in applied position seating of the valve I" in the seat I02 cuts oil escape of pressure from the auxiliary reservoir of the hauling vehicle through the pipe 88.

Under the conditions of an open reservoir pipe the cut-off valve mechanism functions to close off its valve 28 and open pipe 88 to atmosphere, as follows: As soon as the break occurs the rush of air on the release of air from one side of the device causes the ball 48 to move toward the reduced pressure end which, in this instance, where the break occurs beyond the outlet l8, moves the ball 48 against the inner end of the tube 42, thereby preventing the escape of air from the reservoir through the open line 36. Likewise the rush of air upon the release of air from one side of the device causes the balls 50 and II to move toward the reduced pressure end which, in this instance, where the break occurs beyond the outlet I8, moves the ball 50 against its seat and it in turn moves the valve 5| off its seat so that the pipe 88 is then open to atmosphere through the port l8, passages 5, 40, lit to the open pipe 36. As soon as the pipe 88 is open to atmosphere the piston of the triple valve mechanism of the hauling vehicle moves over to brake application position, as previously described, and near the end of its movement it engages and moves the stem lull to open the valve 91. The opening of valve 91 causes compressed air from the pipe 60 to pass through the passage 94, chamber 95, passage 96, pipe IM to port 3! and the chamber above the piston 21, thereby moving the piston 21 and its associated parts to close the valve 20, as previously described, thereby prevcnting the escape of air from the reservoir through the open reservoir pipe extending from the cut-oil valve mechanism l l on the main or hauling vehicle.

It has been noted that the valves 48, 50 and 5| would function whether a reduction occurred at either the arbitrarily designated inlet and H or the outlet end id of the cut-off valve mechanism, and this permits this mechanism to be associated with the main reservoir pressure pipe and the triple valve mechanism of each of the trailer vehicles in the same manner that this cut-oil valve mechanism is associated with said reservoir pipe and the triple valve mechanism of the hauling vehicle, and it may be so used but in practice I have found that this mechanism is not necessary for the satisfactory operation of the triple valve mechanisms of the trailer vehicles. 7

In order to prevent the possibility of excessive escape of air from the auxiliary reservoir, more particularly of the hauling vehicle, when the triple valve is being put into operation, a check valve construction, shown in Fig. 5, may be associated with the pipes 55 and 55. This includes a valve casing ill having a check valve H8 at one end, normally urged to its seat by a spring H5, said check valve having a small bleed hole rec in its head. The casing ill is secured by suitable couplings IS! in the pipe line 55. This check valve permits the air at reservoir pressure to pass through pipe 55 to the auxiliary reservoirs 6i but restricts the passage of air in the reverse direction.

From the foregoing description it will be noted that this system provides for the application of the brakes on all the vehicles of the train by straight air with the same facility for eflicient control and application of the brakes on the trailer vehicles as is obtained on the hauling vehicle, and that in case the vehicles pull apart the triple valve mechanisms are brought into operation to automatically apply the brakes on the separated vehicles.

It will be understood that the rear end of the reservoir pipe 36 and that of the train pipe H8 are closed on by the valve I15 at the end of the train, and that the main reservoir 35 is charged with compressed air by any suitable compressor, which is generally associated with the propelling motor of the hauling tractor vehicle.

Reference is here made to my copending application Serial No. 23,847, filed April 17, 1925, for Brake control valve, wherein the control valve mechanisms shown in this system are more specifically described and claimed, and since the present application is directed to an air brake system absence of claims to the particular feature of construction of the control valve mechanisms herein is not to be considered as a waiver of claim to invention therefor, as such features have been claimed in the aforementioned application.

I desire it to be understood that this invention is not to be limited to any particular arrangement or construction of parts except insofar as such limitations are included in the claims or necessitated by the prior art.

What I claim as my invention is:

I. In a system for vehicle trains, the combination with the main air reservoir, the reservoir pressure pipe. the brakes of each vehicle. and triple valve mechanism for each vehicle, of means under the control of the operator of the tractor vehicle for effecting an application of the brakes of each vehicle by straight air pressure from the auxiliary reservoirs with the triple valves in a release position and for effecting the release of the brakes through the exhaust passage of the triple valve mechanism, and means for eiiecting the automatic operation of the triple valve mechanism for each vehicle when the reservoir pressure pipe is opened upon a separation of the vehicles.

2. In a vehicle train air brake system, the comblnation with the main compressed air reservoir and the reservoir pressure pipe connected therewith, of triple valve mechanism for each vehicle including an auxiliary reservoir supplied with compressed air from the main reservoir, brake pipes associated with the brakes 01 each vehicle, control valve mechanism associated with the brake pipes and auxiliary reservoir of each vehicle, means under the control of the operator for operating the control valve mechanism of the tractor vehicle, means for operating the control valve mechanism of each trailer vehicle comprising pressure piping connected with the brake pipes of the driving vehicle and receivin compressed air therefrom, and means for eflecting the automatic operation of the triple valve mechanism of each vehicle to supply its brake pipes with compressed air when the reservoir pressure pipe is opened upon the separation of the vehicles.

3. In a vehicle train air brake system, the combination with the brake pipe of each vehicle, the main compressed air reservoir and the reservoir pressure pipe connected therewith, of triple valve mechanism for each vehicle, means for normaliy maintaining each triple valve mechanism in release position, means, under the control of the operator, for admitting compressed air from the auxiliary reservoir of each vehicle to the brake pipe for that vehicle to make a brake application and for efiecting the release of the braking pressure through the exhaust passage of the triple valve mechanlsm, the triple valve mechanism of the trailer vehicles operating automatically to supply compressed air from their respective reservoirs to their respective brake pipes when the reservoir pressure pipe is opened by a separation of the vehicles, and automatic valve mechanism associated with the triple valve mechanism of the tractor vehicle for preventing the escape of compressed air from the main reservoir upon a separation of the parts of the reservoir pipe and permitting the triple valve on said tractor vehicle to function.

4. In a vehicle train air brake system, the combination with the main reservoir, the reservoir pressure pipe, the brake pipes and the triple valve mechanism of each vehicle, of control valve mean mechanism associated with the brake pipes and auxiliary reservoir of each vehicle, means under the control of the operator for operating the control valve mechanism of the tractor vehicle, means for operating the control valve mechanism of the trailer vehicles by compressed air from the brake pipes of the tractor vehicle, and means for effecting the automatic operation of the triple valve mechanism of each vehicle to supply its brake pipes with compressed air when the reservoir pipe is opened upon the separation of the vehicles.

5. In an air brake system, triple valve mechanlsm having an auxiliary reservoir. :3. cylinder. an operating piston and inlet and exhaust valves operatively associated with said piston in combination with a passage at the front end of said cylindo: and valve means on said piston adapted to close said passage when said piston has moved to brake-applying position to prevent escape of compressed air from the auxiliary reservoir.

6. In an air brake system, triple valve mechanism comprising an auxlilary reservoir, 9. cylinder, an operating piston and inlet and exhaust valves operatively associated with said piston, means for balancing the air pressure on both sides of said piston, spring means for moving said piston to release" position, and means for unbalancing the air pressures on said piston to cause said piston to move to brake-application position, and including a port at the head end of said cylinder, and means on the piston to close said port when the piston has moved to brake-applying position to prevent escape of compressed air from the auxiliary reservoir.

'7. In an air brake system, the combination of the reservoir pressure pipe and cut-off valve mechanism including an air-operated cut-off valve in said pipe, of tripe valve mechanism including an auxiliary reservoir, a cylinder, an operating piston, and a control valve associated with said auxiliary reservoir and opened by its movement to bral e-applying position to supply compressed air to move said cut-off valve to closed position.

8. In an air brake system, triple valve mechanism in combination with cut-off valve mechanism for the reservoir pressure pipe, the triple valve mechanism including an auxiliary reser vcir, a cylinder, :5. valve-actuating piston in said cylinder, said cylinder having a passage at its front, end, and a. cut-cff-operating valve opened by said piston upon its movement to brake-applying position, said cut-oil valve mechanism ineluding a cut-off-valve-controlled reservoir pressure conduit, and a pair of valve-controlled ports communicating with both ends of said conduit, one of said ports communicating with said passage in the front end of said cylinder, the other said ports communicating with the auxiliary reservoir, and means operated by compressed air from the auxiliary reservoir when said cut-oil'- operatlng valve is open to close said cut-oil valve.

9. In an air brake system. the combination with the reservoir pressure pipe of cut-oft valve mechanism including a. casing having a conduit. a valve controlling the passage or air through said conduit, said casing having passages and ports connected with saldconduit on opposite sides of said valve, a valve adapted to close oil one set of passages leading to one of said ports upon a decrease in pressure at the passage being closed 011, and a pair of valves associated with the other port and said passages movable to close one of said passage: and to establish communication be- '16 tween said other port and the reduced pressure end of said conduit.

10. In air brake system for vehicle trains, the combination with the main reservoir, the reservoir pressure pipes, the brake-applying devices of each vehicle and triple valve mechanism of each vehicle, of means under the control of the operator of the tractor vehicle for operating said brake-applying devices without operating the triple valves of the triple valve mechanisms. and means for effecting the automatic operation of the triple valve mechanism of each vehicle when the reservoir pipe is opened upon the separation of any 01' the couplings for said pipe between the vehicles.

11. In an air brake system for vehicle trains, the combination with the main reservoir, the reservoir pressure pipe, and the brake pipes and brake-applying devices of each vehicle, of a single control valve mechanism for direct control of the operationof the brake-applying devices of each vehicle, means, under the control of the operator, for operating the control valve mechanism of the tractor vehicle, and means controlled by compressed air introduced into the brake pipes of the tractor vehicle by the operation of its control valve mechanism for operating the control valve mechanism of each trailer vehicle. 12. In an air brake system for vehicle trains, the combination with the main reservoir, the reservoir pressure pipe, the brake-applying devices of each vehicle and the triple valve mechanism of each vehicle, 0! control valve mechanism associated with the brake-applying device and auxiliary reservoir of each vehicle, means, under the control of the operator, for operating the control valve mechanism of the tractor vehicle, means controlled by the operation of the control valve mechanism of said tractor vehicle for operating the control valve mechanism of each trailer vehicle, and means for efiecting the operation of the triple valve mechanism of each vehicle to automatically operate said brake-applying devices when parts of the reservoir pipe become separated upon the separation of the vehicles.

13. In a vehicle train air brake system, the combination with the main reservoir, the reservoir pressure pipe, the brakes of each vehicle and triple valve mechanism for each trailer vehicle, of means under the control of the operator oi the tractor vehicle for effecting an application of the brakes of each vehicle by straight air pressure with the triple valves of the trailer vehicles in a release position and for effecting the release of the brakes of the trailer vehicles through the exhaust passage of their triple valve mechanisms, and means for effecting the automatic operation of the triple valve mechanism for each trailer vehicle when the reservoir pressure pipe is opened upon a separation of the vehicles. I

14. In a vehicle train air brake system, the combination with the main compressed air reservoir, the reservoir pressure pipe connected therewith and the brake for each vehicle, of triple valve mechanism for each trailer vehicle and tractor vehicle, brake pipes associated with the brake of each trailer vehicle, vehicle control valve mechanism associated with the brake pipes of the tractor vehicle, vehicle control valve mechanism associated with the auxiliary reservoir of each of the trailer vehicles and rendered operative by compressed air controlled directly by the operation of the control valve mechanism of the tractor vehicle, means under the control of the operator for operating the control valve mechanism of the tractor vehicle, and means for effecting the automatic operation of the triple valve mechanism of each trailer vehicle and the tractor vehicle to supply its brake pipes with compressed air when the reservoir pressure pipe is opened upon the separation of the vehicles.

15. In a fluid pressure brake system for vehicle trains, the combination of a brake applying device for each vehicle, a control valve mechanism for controlling the operation of the brake applying device of each vehicle, means under the control of the operator for operating the control valve mechanism of the tractor vehicle, means rendered operative by the operation of the control valve mechanism of said tractor vehicle for operating the control valve mechanism of each trailer vehicle, and means (not included in the control valve operating means) for communication of actuating fluid with the brake applying devices of each vehicle.

NIELS A. CHRISTENSEN. 

